Magnetic lithographic ink



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Ser. No. 767,093. This application Aug. 23, 1960,

Ser. No. 51,29l

2 Claims. (Cl. 252-4325) This invention relates to magnetic ink for usein lithographic duplicating machines to produce copy capable of beingread. with the magnetic reading head in automatic,

high speed, scanning devices.

This is a continuation of my copending application Serial Number767,093, now abandoned, entitled Magnetic Lithographic Ink, filedOctober 14, 1958.

It relates more particularly to a lithographic duplicating ink embodyingcharacteristics essential for use with magnetic read-out devices and acomponent or better wetout of the paper to produce a full image such aswould be desirable for successful operation in magnetic read-out.

It is an object of this invention to product a magnetic ink havinglithographic properties for use in lithographic duplicating machines toproduce magnetic printing, and it is a related object to produce alithographic ink of the type described containing a. magnetic componentin the form of a magnetic iron oxide; which produces easily readable andwell defined copy; which produces a full and complete image; which doesnot feed back into the fountain solution of the lithographic duplicatingmachine thereby to keep the fountain free of contaminating magneticparticles; which produces copy having sufficient magnetic strength foreificient and proper read-out, and which is capable of producing a largemember of copies of good quality. y

In accordance with the practice of this invention, a magnetic ink forlithographic duplication is formulated of the combination of thefollowing materials present in amounts as hereinafter set forth.

EXAMPLE 1 Magnetic Ink Composition (Broad) Percent by weightLithographic vehicle or varnish -60 Magnetic iron oxide -70 Toners ortinctorial agents 1-20 Lecithin 1-5 Lithographic ink varnishes are wellknown to the trade. They usually comprise a base capable of fluid flow.The base may be a bodied oil, such as linseed oil, or a hydrocarbon, oran oil from the synthetic resinous materials such as alkyd resin or aphenolformaldehyde resin. The following are classes of varnishes whichcan be used:

Linseed modified phenol formaldehyde varnish Bodied linseed oil varnishMaleic-alkyd varnish Pentaerythritol alkyd varnish Hydrocarbon varnishIt is preferred to. make use of a lithographic varnish giving a highdegree of Water repellency to'the copy. A suitable varnish is marketedby General Printing Ink Company under the designation No. 01269.

As to the magnetic iron oxide, use can be made of Bfldli'il iatentedMar. 19, l9i3 ice pany of Easton, Pennsylvania, under the trade nameIRNlOO.

The toner comprises a tinctorial agent to impart a desired shade andreadability to the copy. Use can be made of such conventional toners ascarbon black, lamp black, alkali blue, iron blue, and other dyestuffsand pigments. They may be incorporated as a dry pigment or as adispersion in varnish oils for introduction into the composition.

The surface active agent functions also as a wetting agent for thepigment, and for wet-out of the surface upon which the magnetic ink isdeposited in printing to produce a full and complete image. For thispurpose, best use can be made of a lecithin. A suitable material (soybean licithin) is marketed by American Lecithin Company,

Long Island City, New York, under the trade name Alcolec 410N.

The following are specific examples of magnetic lithographic inksprepared in accordance with the practice of this invention:

EXAMPLE 2 It will be understood that the amounts of the. components maybe varied within the range described to provide the desired viscositycharacteristics which can best be determined by trial and error.

For example, in a preferred range. the varnish made up of bodied oil ora resin or oil modified resin, alone or in combination with an oil, suchas linseed oil, may be employed in an amount within the range of 20-45%by weight; the magnetic iron oxide may be employed in an amount withinthe range of 45-60% by weight; the surface active agent, such aslecithin, may be employed in an amount within the range of 1-5 byweight, and the tinctorial agent, such as carbon black, iron blue andthe like, alone or in combination, may be employed in an amount withinthe range of 1-5 by weight.

The materials may be incorporated in any order but it is best to mix allof the ingredients and then to grind the material inconventional-machines for the preparation of an ink.

It will be understood that changes may be made in the details of theformulation and composition without depart- (3. ing from thespirit f thei lention, especially as defined References Citezi in the file of thispatent m claims UNITED STATES PATENTS A magnetic gr phic link consistingessentially 2,649,381 Hgmpcl et a1 Aug. 18 1953 of wmbifiation of 2 -60%by Weight lithographic 2,688,649 Bjorksm Sam 7, 1954 varnish, -70% byweight magnetic iron oxide, 1-20% by weight tinctoriai agent, and 15% byweight lecithin. OTHER REFERENCES 2. A magnetic, lithographic inkconsisting essentially of D the combination f 2 5 by weight lithographicWolfe: Printing and Litho Inks, 4th ed., Macnan- Dornish, -60% by weightmagnetic iron oxide, 1-5% by 10 land New York, 1949, PP- weighttinctorial agent, and 1-5% by weight lecithin. 161-162, 176-183, 187,205, 232, 270-276.

1. A MAGNETIC, LITHOGRAPHIC LINK CONSISTING ESSENTIALLY OF THECOMBINATION OF 20-60% BY WEIGHT LITHOGRAPHIC VARNISH, 25-70% BY WEIGHTMAGNETIC IRON OXIDE, 1-20% BY WEIGHT TINCTORIAL AGENT, AND 1-5% BYWEIGHT LECITHIN.